Fix memory leak in XNNPACK/MaxPool2D. (#41874)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/41874
Test Plan: Imported from OSS
Reviewed By: ann-ss
Differential Revision: D22699598
Pulled By: AshkanAliabadi
fbshipit-source-id: fec59ed3d5d23bd9197349057fcf2ce56a2b278b
